The British Journal of Psychiatry
The Amnesic and Therapeutic Effects of Bilateral and Unilateral ECT
C. G. COSTELLO, G. P. BELTON, J. C. ABRA, B. E. DUNN

Abstract

Prior to their first experience with ECT, 30 depressed patients learned a list of paired words and were tested for recall, recognition, and relearning of this list after the fourth and after the last shocks of their individual series of treatments. Cerebral dominance was assessed before treatment by the Harris Tests of Lateral Dominance and only right-handed patients included.

Patients who received shocks to the non-dominant (right) hemisphere did better on recall and relearning tasks than those receiving shocks bilaterally or unilaterally to the dominant hemisphere. Recognition scores of both unilateral groups were significantly better than those of the bilateral group. Shocks after the first four also produced differential recall loss.

The dominant hemisphere seems thus more closely associated with recall and relearning, while recognition is associated with both hemispheres. The findings are discussed in terms of dual process and unitary process models of memory.

Analyses of scores on the Beck and Costello-Comrey self-report depression scales provided no evidence for differences in therapeutic benefit between the three modes of ECT. Unilateral non-dominant ECT may therefore represent the most efficient treatment.